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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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2nd Feb 2011, 1:14 pm | #41 |
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Re: Joystick VFA
I know a few comments have been made about the effectiveness of the Joystick but whatever it does, it can radiate a signal.In the late 80's I spent a lot of my spare time messing about with magnetic loops and again whether you like them or hate them, they can put out a signal.
No Antenna is the perfect solution, for me the contact is important not the 59 report. Certainly for reception certain antennae may be 1 or 2 S point down relative to say a dipole however the background noise on reception is a lot down hence received signals do appear at times as more readable. There was a debate a few years ago about the T2FD folded dipole, it worked ok for me , it did not put out the strongest radiated signal but reception was quiet and effective and it worked on Top Band.I thought it was a reasonable compromise. Nowadays I like the QRP stuff and morse and use the best receiver I have available at the time . I am not trying to deflect the thread into another topic but really state that if this thread has interested you in a Joystick , then have a go , just for reception it will be useful. Mike Last edited by MichaelR; 2nd Feb 2011 at 1:16 pm. Reason: grammar |
2nd Feb 2011, 3:37 pm | #42 |
Nonode
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Re: Joystick VFA
Hi Onewatt
The documentation mentions special feeder cable. Mine did not have any cable attached. At the moment I am using a piece of heavy duty test lead wire. Can you tell me about the cable on tour two? Thanks Al
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2nd Feb 2011, 7:53 pm | #43 |
Hexode
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Re: Joystick VFA
Hi Al,
I think it was just a heavy duty multi-core cable. I may have an oddment laying around, I'll see if I can dig it out. Onewatt |
1st Mar 2011, 11:03 pm | #44 | |
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Re: Joystick VFA
Quote:
The cable appears to be shielded audio cable, not RF coaxial cable! Although the ends (tuner end) were seperated, as though to be used coaxial fashion, inside the antenna they are in fact shorted together. It could be that the previous owner tried using the antenna thinking it had a coaxial unbalanced feed, whereas it looks as though both the inner and braid were intended to be shorted and used simply as a heavy single wire feed. Either way I aquired the antenna cheap, even though it is in mint condition. The 'feeder' (and I use that term loosely with this antenna) goes through a hole in one end of the Joystick (through what looks like a chair leg plastic cap), where it is tied into a knot (to prevent it coming out I guess), and then finally is attatched to the tube via a solder tag that is rivited to the tube. As mentioned above, both the inner and outer are shorted together where they enter the solder tag, and as far as I can tell this is completely original. I believe that various claims were made with regard to this antennas functionality, many of which seem to border on the 'magical'. My intention is to actually subject the specimen I have to rather more objective testing methods, using modern day analysers etc. It will be interesting to see just what results do come about in the end. Something that always puzzles me about the Joystick antenna is that in a number of drawings and illustrations I've seen, the connecting wire is shown going to the end of the loading coil, yet the few I've seen in the flesh always have the wire connecting to the very end of the tube. I have an advert from 1964 which also shows the wire connecting to the loading coil rather than the end of the antenna. Any ideas anyone? Was it just artistic license, or did Mr P. change his design at some point? The bumph connected with this antenna also seems to suggest that you can use any length of connecting wire, but of course this will radiate too, probably better than the Joystick itself! 73 for now, Mark. |
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5th Mar 2011, 1:27 pm | #45 |
Hexode
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Re: Joystick VFA
Hi
I just noticed in my last post I had misleadingly put multi-core instead of multi-stranded. I'm sure you new what I meant tho! Onewatt
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24th Mar 2011, 2:10 pm | #46 |
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Re: Joystick VFA
Guess what I have just found in my loft? A VFA, what a treasure. The top section was moving so I took it apart, the broom stale had broke so I shall get a suitable dowel and repair the thing, should work great on the hf bands when mended, hi.
Ben. |
17th May 2011, 12:51 pm | #47 |
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Re: Joystick VFA
I had a Partridge Joystick; I bought it at the Leeds Rally in 1980. It worked as my "HF listening" aerial for some years (I was a G8 at the time). When it finally came down, I discovered that the wire of the coil was Aluminium (about 1/10th in diameter).
I'm working on building one, for use with my FT817, when out in the caravan. I'd value some thoughts on whether one can (should?) use a decent-sized insulated wire for the coil as I have quite a few Km of it on various spools. The two metal pipes are 3' long, each, and the gap in the middle is a broom stave, suitably varnished. Last edited by Dave UXB; 17th May 2011 at 1:00 pm. |
17th May 2011, 2:56 pm | #48 |
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Re: Joystick VFA
The dielectric of the insulation has a small effect on the length required.
I use a "CB silver stick" for portable use on FT817ND, with internal base coil removed and the screw hose clamps for telescopic sections replaced by the kind with "butterfly" finger/thumb operated kind. It's nearly 6m / 20' fully extended. I clamp it to tow eye at rear of car when parked. I use a Elecraft T1 autotuner with it for 40m to 10m. It's just usable to transmit on 80m and 6m too (extend it slightly less for 6m). Of course on the Racal syncal 30 with internal "tuner" it works at 1.8MHz. Also picks up R4 LW on the FT187! Cost about £26 from Rocket Radio in UK. |
18th May 2011, 10:59 am | #49 |
Rest in Peace
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Re: Joystick VFA
As the Joystick VFA is little more than a capacity hat on the end of the 'feeder' (which IMHO is the real radiator in most circumstances) it doesn't matter too much what you make it of, or where on it you attach the 'feeder'.
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8th Jun 2011, 3:47 pm | #50 |
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Re: Joystick VFA
OK, so the main bits are made. Three feet of tubular metal either side of a multi-turn (like: "hundreds - I lost count") coil.
What sort of terminal impedance can I expect; high or low ? (it matters for the selection of the ATU /Balun/ UnUn, etc). Any views please? |
8th Jun 2011, 4:19 pm | #51 |
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Re: Joystick VFA
Depends on band and length of 'feeder'. Could be almost any impedance.
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8th Jun 2011, 11:36 pm | #52 | |
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Re: Joystick VFA
Quote:
It's for HF and the feeder will be about 20ft I reckon. It would be nice to think I could work on 80m (and I'd love to try Top Band). The coil is spread over a couple of feet in the middle. I think it is resonant at about 55 MHz (on my MFJ Antenna Analyser), but more work is needed. |
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9th Jun 2011, 12:21 pm | #53 |
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Re: Joystick VFA
If the VFA itself is resonating at 55MHz (which seems rather high to me - are you sure?) then at any frequency substantially below that it will look like a capacitance on the end of the 'feeder'. Your MFJ will tell what impedance the whole thing has at other freqs, but I would expect for the LF bands a high capacitive impedance with a little radiation resistance in series.
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18th Jul 2011, 6:03 am | #54 |
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Re: Joystick VFA
I've just bought a Joymatch. No info available, but it's red, looks like 3 knobs ("pi"?) but it was not much money and looks in good condition outside.
I'm working away from home and it'll be a couple of weeks before I get home to see it but I'm looking forward to getting back to the shack to inspect it inside! Last edited by Brian R Pateman; 18th Jul 2011 at 12:35 pm. Reason: FRC - Section C. |